This invention relates to a fixing device of the type to be used for fastening a decorative panel to a metal panel in a face-to-face union. More particularly the invention relates to an improved fixing device which is effectively used such as when a decorative panel serving to line an automobile door is fastened to the inner surface of the door.
Generally, the decorative panel which is used such as in lining the automobile body has its base plate coated on the surface with a sheeting material such as fabric or vinyl leather. When the decorative panel is fixed to the inner side of the automobile door, therefore, there must be retained a relationship that said sheeting material is attached fast on its rear surface to the door. For this reason, the fixing device used for fastening the decorative panel of this type generally has a construction such that it can be inserted on the fitting side of the decorative panel. Prior to the attachment of the decorative panel to the inside of the automobile door, this fixing device is inserted in the decorative panel in such a manner that, when the decorative panel is brought to confront the inside of the door, the engaging portion of the fixing device poses itself just in front of the fitting hole perforated in advance in the inside panel of the door. Then, the fixing device is forcibly driven into tight engagement with the fixing hole as by striking the surface of the decorative panel with a hammer, bringing the decorative panel into fast union with the inside of the door.
The fixing devices of this kind which have been suggested to date have a general construction which comprises a head portion adapted to be attached to the decorative panel and an engaging portion adapted to be engaged with the fitting hole perforated in a metal panel such as the inside sheet of the automobile door. The hear portion has two flanges, one larger than the other, opposed to each other across an intervening neck and the engaging portion has a shaft (or stud) extending from the outer surface of one of said flanges in the axial direction of the neck and shoulder means protruding radially from the outer surface of the shaft. The use of this device is accomplished by inserting the small-diameter flange of said head portion from behind the decorative panel into the fitting hole perforated in said panel until the neck is fully pierced through the hole and the panel is held securely between the small-diameter flange and large-diameter flange, bringing the aforementioned engaging portion to a position directly opposite the fitting hole in the panel simultaneously with opposing the decorative panel face to face to the metal panel as described above and subsequently hammering the shoulder means into hooked engagement with the edge of the fitting hole for thereby immobilizing the decorative panel against the metal panel.
Since the conventional fixing device can be fitted into position from behind the decorative panel and the fast engagement of the device with the metal panel can be accomplished simply by hammering the device from above the surface of the decorative panel overlying the device, the device is not affected in any way by the kind of the sheet-shaped cover and the decorative panel can be joined with the metal panel with ample tightness. Conversely, once the conventional fixing device is fastened to the panel by its engaging portion being driven home in the hole perforated in the panel, the shoulder means which have advanced past the perforated hole are brought into permanent engagement with the edge on the rear side of the hole and the device itself generally possesses no means of breaking this engagement. When there arises necessity for removing the decorative panel as when some built-in parts in the automobile door are to be replaced or given repairs, for example, the fixing device may be broken by removal. If, in this case, the removal of the decorative panel is accomplished simply by breaking the fixing device, then the damage to be suffered may be slight. Since the decorative panel is generally made of a material more brittle than the metal panel, however, it often happens that the decorative panel itself or the edge of the hole perforated in the decorative panel for admitting the head portion of the fixing device is broken sooner than the fixing device.
This invention has been accomplished with a view to solving the various problems described above. It is, accordingly, an object of this invention to provide a fixing device which is so adapted that the fixing device, when driven into a supporting panel of high strength such as a metal panel by the pressure applied from above the surface of a decorative panel in much the same way as the conventional fixing device, enables the decorative panel to be fastened onto the supporting panel and, on the other hand, where there arises necessity for removing the decorative panel from the supporting panel, the engagement between the two panels can easily be broken by forcing a suitable tool into the crack between the supporting panel and the decorative panel and prying the fixing device out of position.